diff options
author | Gregory Bean <gbean@codeaurora.org> | 2010-11-24 11:53:52 -0800 |
---|---|---|
committer | Daniel Walker <dwalker@codeaurora.org> | 2010-11-30 13:51:52 -0800 |
commit | 70cc2c00d7471f21120befeb7fc107c856e3985b (patch) | |
tree | 1f1068aab542f5d6ccbf6ea6e800750d3ca6dcf5 /arch/arm/mach-msm/gpio-v2.c | |
parent | 0cc2fc1f2f5f1fcf6699b43d73ca3e753ef63582 (diff) |
msm: gpio: Add irq support to v2 gpiolib.
Complete the MSM v2 gpio subsystem by adding irq_chip.
Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Diffstat (limited to 'arch/arm/mach-msm/gpio-v2.c')
-rw-r--r-- | arch/arm/mach-msm/gpio-v2.c | 309 |
1 files changed, 286 insertions, 23 deletions
diff --git a/arch/arm/mach-msm/gpio-v2.c b/arch/arm/mach-msm/gpio-v2.c index d907af68c8e..0de19ec74e3 100644 --- a/arch/arm/mach-msm/gpio-v2.c +++ b/arch/arm/mach-msm/gpio-v2.c @@ -15,7 +15,13 @@ * 02110-1301, USA. * */ +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/bitmap.h> +#include <linux/bitops.h> #include <linux/gpio.h> +#include <linux/init.h> +#include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/module.h> @@ -27,29 +33,103 @@ /* Bits of interest in the GPIO_IN_OUT register. */ enum { - GPIO_IN_BIT = 0, - GPIO_OUT_BIT = 1 + GPIO_IN = 0, + GPIO_OUT = 1 +}; + +/* Bits of interest in the GPIO_INTR_STATUS register. + */ +enum { + INTR_STATUS = 0, }; /* Bits of interest in the GPIO_CFG register. */ enum { - GPIO_OE_BIT = 9, + GPIO_OE = 9, +}; + +/* Bits of interest in the GPIO_INTR_CFG register. + * When a GPIO triggers, two separate decisions are made, controlled + * by two separate flags. + * + * - First, INTR_RAW_STATUS_EN controls whether or not the GPIO_INTR_STATUS + * register for that GPIO will be updated to reflect the triggering of that + * gpio. If this bit is 0, this register will not be updated. + * - Second, INTR_ENABLE controls whether an interrupt is triggered. + * + * If INTR_ENABLE is set and INTR_RAW_STATUS_EN is NOT set, an interrupt + * can be triggered but the status register will not reflect it. + */ +enum { + INTR_ENABLE = 0, + INTR_POL_CTL = 1, + INTR_DECT_CTL = 2, + INTR_RAW_STATUS_EN = 3, +}; + +/* Codes of interest in GPIO_INTR_CFG_SU. + */ +enum { + TARGET_PROC_SCORPION = 4, + TARGET_PROC_NONE = 7, }; + +#define GPIO_INTR_CFG_SU(gpio) (MSM_TLMM_BASE + 0x0400 + (0x04 * (gpio))) #define GPIO_CONFIG(gpio) (MSM_TLMM_BASE + 0x1000 + (0x10 * (gpio))) #define GPIO_IN_OUT(gpio) (MSM_TLMM_BASE + 0x1004 + (0x10 * (gpio))) +#define GPIO_INTR_CFG(gpio) (MSM_TLMM_BASE + 0x1008 + (0x10 * (gpio))) +#define GPIO_INTR_STATUS(gpio) (MSM_TLMM_BASE + 0x100c + (0x10 * (gpio))) + +/** + * struct msm_gpio_dev: the MSM8660 SoC GPIO device structure + * + * @enabled_irqs: a bitmap used to optimize the summary-irq handler. By + * keeping track of which gpios are unmasked as irq sources, we avoid + * having to do readl calls on hundreds of iomapped registers each time + * the summary interrupt fires in order to locate the active interrupts. + * + * @wake_irqs: a bitmap for tracking which interrupt lines are enabled + * as wakeup sources. When the device is suspended, interrupts which are + * not wakeup sources are disabled. + * + * @dual_edge_irqs: a bitmap used to track which irqs are configured + * as dual-edge, as this is not supported by the hardware and requires + * some special handling in the driver. + */ +struct msm_gpio_dev { + struct gpio_chip gpio_chip; + DECLARE_BITMAP(enabled_irqs, NR_GPIO_IRQS); + DECLARE_BITMAP(wake_irqs, NR_GPIO_IRQS); + DECLARE_BITMAP(dual_edge_irqs, NR_GPIO_IRQS); +}; static DEFINE_SPINLOCK(tlmm_lock); +static inline struct msm_gpio_dev *to_msm_gpio_dev(struct gpio_chip *chip) +{ + return container_of(chip, struct msm_gpio_dev, gpio_chip); +} + +static inline void set_gpio_bits(unsigned n, void __iomem *reg) +{ + writel(readl(reg) | n, reg); +} + +static inline void clear_gpio_bits(unsigned n, void __iomem *reg) +{ + writel(readl(reg) & ~n, reg); +} + static int msm_gpio_get(struct gpio_chip *chip, unsigned offset) { - return readl(GPIO_IN_OUT(offset)) & BIT(GPIO_IN_BIT); + return readl(GPIO_IN_OUT(offset)) & BIT(GPIO_IN); } static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int val) { - writel(val ? BIT(GPIO_OUT_BIT) : 0, GPIO_IN_OUT(offset)); + writel(val ? BIT(GPIO_OUT) : 0, GPIO_IN_OUT(offset)); } static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset) @@ -57,8 +137,7 @@ static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset) unsigned long irq_flags; spin_lock_irqsave(&tlmm_lock, irq_flags); - writel(readl(GPIO_CONFIG(offset)) & ~BIT(GPIO_OE_BIT), - GPIO_CONFIG(offset)); + clear_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset)); spin_unlock_irqrestore(&tlmm_lock, irq_flags); return 0; } @@ -71,8 +150,7 @@ static int msm_gpio_direction_output(struct gpio_chip *chip, spin_lock_irqsave(&tlmm_lock, irq_flags); msm_gpio_set(chip, offset, val); - writel(readl(GPIO_CONFIG(offset)) | BIT(GPIO_OE_BIT), - GPIO_CONFIG(offset)); + set_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset)); spin_unlock_irqrestore(&tlmm_lock, irq_flags); return 0; } @@ -87,30 +165,215 @@ static void msm_gpio_free(struct gpio_chip *chip, unsigned offset) msm_gpiomux_put(chip->base + offset); } -static struct gpio_chip msm_gpio = { - .base = 0, - .ngpio = NR_GPIO_IRQS, - .direction_input = msm_gpio_direction_input, - .direction_output = msm_gpio_direction_output, - .get = msm_gpio_get, - .set = msm_gpio_set, - .request = msm_gpio_request, - .free = msm_gpio_free, +static int msm_gpio_to_irq(struct gpio_chip *chip, unsigned offset) +{ + return MSM_GPIO_TO_INT(chip->base + offset); +} + +static inline int msm_irq_to_gpio(struct gpio_chip *chip, unsigned irq) +{ + return irq - MSM_GPIO_TO_INT(chip->base); +} + +static struct msm_gpio_dev msm_gpio = { + .gpio_chip = { + .base = 0, + .ngpio = NR_GPIO_IRQS, + .direction_input = msm_gpio_direction_input, + .direction_output = msm_gpio_direction_output, + .get = msm_gpio_get, + .set = msm_gpio_set, + .to_irq = msm_gpio_to_irq, + .request = msm_gpio_request, + .free = msm_gpio_free, + }, +}; + +/* For dual-edge interrupts in software, since the hardware has no + * such support: + * + * At appropriate moments, this function may be called to flip the polarity + * settings of both-edge irq lines to try and catch the next edge. + * + * The attempt is considered successful if: + * - the status bit goes high, indicating that an edge was caught, or + * - the input value of the gpio doesn't change during the attempt. + * If the value changes twice during the process, that would cause the first + * test to fail but would force the second, as two opposite + * transitions would cause a detection no matter the polarity setting. + * + * The do-loop tries to sledge-hammer closed the timing hole between + * the initial value-read and the polarity-write - if the line value changes + * during that window, an interrupt is lost, the new polarity setting is + * incorrect, and the first success test will fail, causing a retry. + * + * Algorithm comes from Google's msmgpio driver, see mach-msm/gpio.c. + */ +static void msm_gpio_update_dual_edge_pos(unsigned gpio) +{ + int loop_limit = 100; + unsigned val, val2, intstat; + + do { + val = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN); + if (val) + clear_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio)); + else + set_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio)); + val2 = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN); + intstat = readl(GPIO_INTR_STATUS(gpio)) & BIT(INTR_STATUS); + if (intstat || val == val2) + return; + } while (loop_limit-- > 0); + pr_err("dual-edge irq failed to stabilize, " + "interrupts dropped. %#08x != %#08x\n", + val, val2); +} + +static void msm_gpio_irq_ack(unsigned int irq) +{ + int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq); + + writel(BIT(INTR_STATUS), GPIO_INTR_STATUS(gpio)); + if (test_bit(gpio, msm_gpio.dual_edge_irqs)) + msm_gpio_update_dual_edge_pos(gpio); +} + +static void msm_gpio_irq_mask(unsigned int irq) +{ + int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq); + unsigned long irq_flags; + + spin_lock_irqsave(&tlmm_lock, irq_flags); + writel(TARGET_PROC_NONE, GPIO_INTR_CFG_SU(gpio)); + clear_gpio_bits(INTR_RAW_STATUS_EN | INTR_ENABLE, GPIO_INTR_CFG(gpio)); + __clear_bit(gpio, msm_gpio.enabled_irqs); + spin_unlock_irqrestore(&tlmm_lock, irq_flags); +} + +static void msm_gpio_irq_unmask(unsigned int irq) +{ + int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq); + unsigned long irq_flags; + + spin_lock_irqsave(&tlmm_lock, irq_flags); + __set_bit(gpio, msm_gpio.enabled_irqs); + set_gpio_bits(INTR_RAW_STATUS_EN | INTR_ENABLE, GPIO_INTR_CFG(gpio)); + writel(TARGET_PROC_SCORPION, GPIO_INTR_CFG_SU(gpio)); + spin_unlock_irqrestore(&tlmm_lock, irq_flags); +} + +static int msm_gpio_irq_set_type(unsigned int irq, unsigned int flow_type) +{ + int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq); + unsigned long irq_flags; + uint32_t bits; + + spin_lock_irqsave(&tlmm_lock, irq_flags); + + bits = readl(GPIO_INTR_CFG(gpio)); + + if (flow_type & IRQ_TYPE_EDGE_BOTH) { + bits |= BIT(INTR_DECT_CTL); + irq_desc[irq].handle_irq = handle_edge_irq; + if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) + __set_bit(gpio, msm_gpio.dual_edge_irqs); + else + __clear_bit(gpio, msm_gpio.dual_edge_irqs); + } else { + bits &= ~BIT(INTR_DECT_CTL); + irq_desc[irq].handle_irq = handle_level_irq; + __clear_bit(gpio, msm_gpio.dual_edge_irqs); + } + + if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH)) + bits |= BIT(INTR_POL_CTL); + else + bits &= ~BIT(INTR_POL_CTL); + + writel(bits, GPIO_INTR_CFG(gpio)); + + if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) + msm_gpio_update_dual_edge_pos(gpio); + + spin_unlock_irqrestore(&tlmm_lock, irq_flags); + + return 0; +} + +/* + * When the summary IRQ is raised, any number of GPIO lines may be high. + * It is the job of the summary handler to find all those GPIO lines + * which have been set as summary IRQ lines and which are triggered, + * and to call their interrupt handlers. + */ +static void msm_summary_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + unsigned long i; + + for (i = find_first_bit(msm_gpio.enabled_irqs, NR_GPIO_IRQS); + i < NR_GPIO_IRQS; + i = find_next_bit(msm_gpio.enabled_irqs, NR_GPIO_IRQS, i + 1)) { + if (readl(GPIO_INTR_STATUS(i)) & BIT(INTR_STATUS)) + generic_handle_irq(msm_gpio_to_irq(&msm_gpio.gpio_chip, + i)); + } + desc->chip->ack(irq); +} + +static int msm_gpio_irq_set_wake(unsigned int irq, unsigned int on) +{ + int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, irq); + + if (on) { + if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS)) + set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 1); + set_bit(gpio, msm_gpio.wake_irqs); + } else { + clear_bit(gpio, msm_gpio.wake_irqs); + if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS)) + set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 0); + } + + return 0; +} + +static struct irq_chip msm_gpio_irq_chip = { + .name = "msmgpio", + .mask = msm_gpio_irq_mask, + .unmask = msm_gpio_irq_unmask, + .ack = msm_gpio_irq_ack, + .set_type = msm_gpio_irq_set_type, + .set_wake = msm_gpio_irq_set_wake, }; static int __devinit msm_gpio_probe(struct platform_device *dev) { - int ret; + int i, irq, ret; + + bitmap_zero(msm_gpio.enabled_irqs, NR_GPIO_IRQS); + bitmap_zero(msm_gpio.wake_irqs, NR_GPIO_IRQS); + bitmap_zero(msm_gpio.dual_edge_irqs, NR_GPIO_IRQS); + msm_gpio.gpio_chip.label = dev->name; + ret = gpiochip_add(&msm_gpio.gpio_chip); + if (ret < 0) + return ret; - msm_gpio.label = dev->name; - ret = gpiochip_add(&msm_gpio); + for (i = 0; i < msm_gpio.gpio_chip.ngpio; ++i) { + irq = msm_gpio_to_irq(&msm_gpio.gpio_chip, i); + set_irq_chip(irq, &msm_gpio_irq_chip); + set_irq_handler(irq, handle_level_irq); + set_irq_flags(irq, IRQF_VALID); + } - return ret; + set_irq_chained_handler(TLMM_SCSS_SUMMARY_IRQ, + msm_summary_irq_handler); + return 0; } static int __devexit msm_gpio_remove(struct platform_device *dev) { - int ret = gpiochip_remove(&msm_gpio); + int ret = gpiochip_remove(&msm_gpio.gpio_chip); if (ret < 0) return ret; |